RE: Can I run Linux without a file system?

There are people here who can help you more than I, but I'll take a gander.
This is what I believe to be correct:
Yes. You will always have SOME kind of filesystem. But this begs another
question. How much do you know about Linux, and what are you really asking?
The /proc filesystem is not really on any disk, just like /dev (I think)
isn't on any disk, though they look like to us users that they are
filesystems.

If you want to run a program, where will it come from? There are filesystems
made for RAM, like cramfs or ramdisks, or flash filesystems complete with
wear-leveling. Maybe you can just jump to an offset and start executing code
if all you have is just a kernel and a program. If that is the case then
maybe you'll have to call your program 'init' or change the source of the
kernel to invoke your program.

Does this help?

I reserve the right to be wrong.


-----Original Message-----
From: Tim Lai [mailto:laitingwai@yahoo.com]
Sent: Friday, June 21, 2002 11:09 AM
To: linuxppc-embedded@lists.linuxppc.org
Subject: Can I run linux without a file system?



I am porting linux on a custom board.
I am using the bootrom to load vmlinux onto
RAM, and I am in the middle of getting the console/
serial driver to work.
All the documents I read have refer the console as
/dev/ttyS, and state that to communicate to the
console, I have to set it up with open("/dev/ttyS").

Does that means I have to have some sort of file
system in linux?

Thanks.


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Thanks, Jason.
I am new to linux kernel. I'll have the main
application run from init(), so I wasn't planning
to have a file system.

Yes. You will always have SOME kind of filesystem.
But this begs another
question. How much do you know about Linux, and what
are you really asking?

If /proc and /dev is not really on any disk, what do
I have to do to init or create /dev? Do I need ramdisk
as a minumum requirement for linux?
My main goal right now is to get the serial port
to work, so I can do some debugging with the dumb
terminal. After I do tty_register() in the serial
driver, does linux assign /dev/ttyS to this device?

The /proc filesystem is not really on any disk, just
like /dev (I think)
isn't on any disk, though they look like to us users
that they are
filesystems.

Can you give me pointers on which file to read?

Does this help?

Yes. Thank you very much. :)


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Tim,

Maybe initrd and linuxrc is enough for your system. Read the file
initrd.txt in the Linux source tree Documentation sub-directory.

[]'s, Scop                            mailto:scop@vanet.com.br

------------------------------------------------------------------
It might look like I'm doing nothing, but at the cellular level I'm
really quite busy.

Friday, June 21, 2002, 4:35:17 PM, you wrote:


TL> Thanks, Jason.
TL> I am new to linux kernel. I'll have the main
TL> application run from init(), so I wasn't planning
TL> to have a file system.

quoted

Yes. You will always have SOME kind of filesystem.
But this begs another
question. How much do you know about Linux, and what
are you really asking?

TL> If /proc and /dev is not really on any disk, what do
TL> I have to do to init or create /dev? Do I need ramdisk
TL> as a minumum requirement for linux?
TL> My main goal right now is to get the serial port
TL> to work, so I can do some debugging with the dumb
TL> terminal. After I do tty_register() in the serial
TL> driver, does linux assign /dev/ttyS to this device?

quoted

The /proc filesystem is not really on any disk, just
like /dev (I think)
isn't on any disk, though they look like to us users
that they are
filesystems.

TL> Can you give me pointers on which file to read?

quoted

Does this help?

TL> Yes. Thank you very much. :)

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Tim Lai wrote:

I am new to linux kernel. I'll have the main
application run from init(), so I wasn't planning
to have a file system.

So, why are you trying to use Linux?  If you don't start
up applications outside of the kernel, there aren't very
many features that make it attractive or useful.


	-- Dan


** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Well, there is memory protection for now.
And when new hardware arrives, we'll have
file system.

--- Dan Malek <dan@embeddededge.com> wrote:

Tim Lai wrote:

quoted

I am new to linux kernel. I'll have the main
application run from init(), so I wasn't planning
to have a file system.

So, why are you trying to use Linux?  If you don't
start
up applications outside of the kernel, there aren't
very
many features that make it attractive or useful.


	-- Dan

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/